The present invention provides a method and apparatus for weighing articles while the articles are in motion and in particular relates to a method and apparatus for weighing articles, e.g. mail pieces, packages, etc., while the articles are moving at substantial linear speeds.
In many applications, it is desirable to weigh objects while they are moving. For example, in handling large volumes of mail, packages, etc., it is desirable to weigh the article as it is being sorted for delivery to its destination in order to determine the amount of postage required for the article. One such instance occurs when the postage for a particular mail piece is to be charged to a pre-paid “permit”. Each piece has to be weighed and recorded so that the proper postage can be charged back to the permit holder. Normally, this is done by actually weighing each piece with a scale or the like. In other instances, mail pieces are weighed before the proper postage is stamped thereon. Again, this usually requires some manual handling of the articles.
Recently, several automated machines have been proposed to weigh an article such as a letter on the fly; see U.S. Pat. Nos. 5,393,939; 6,107,579; and U.S. Pat. No. 6,940,025 B1.